Apparatus for clamping lining material to brake shoes



April 20, 1954 A. J. KASAK 2,575,850

APPARATUS FOR CLAMPING LINING MATERIAL T0 BRAKE SHOES Filed Jan. 2:, 1951 14 Sheets-Sheet 1 IN V EN TOR 14/3/7'0A/M/J KASAK AT TORNE. Y

.April 20, 1954 A. J. KASAK 2,675,850

APPARATUS FOR CLAMPING LINING MATERIAL TO BRAKE SHOES Filed Jan. 23, 1951 l4 Sheets-Sheet 2 42 2 2- LZ m 226 ma 18 F o A8 42 ma 42 INVENTOR ATTORNEY April 20, 1954 A. J. KASAK 2,675,850

APPARATUS FOR CLAMPING LINING MATERIAL TO BRAKE SHOES Filed Jan. 25, 1951 14 Sheets-Sheet 5 ATTORNEY Y A. J. KA'SAK 2,675,850

APPARATUS FOR CLAMPING LINING MATERIAL TO BRAKE SHOES April 20, 1954 14 Sheets-Sheet 4 Filed Jan. 25, 1951 INVENTOR 14/V TO/V/IV J MOW/f ATTORNEY April 20, 1954 A. J. KASAK APPARATUS FOR CLAMPING LINING MATERIAL TO BRAKE SHOES Filed Jan. 23, 1951 14 Sheets-Sheet 5 IN VEN TOR Agra/mm m 54K XMM ' ATTORNEY April 20, 1954 A. J. KASAK 2,675,850

APPARATUS FOR CLAMPING LINING MATERIAL 1'0 BRAKE SHOES Fil ed Jan. 25, 1951 14 Sheets-Sheet 6 IN VEN TOR J g/70mm J Mum XMM AT TORNEY Filed Jan. 23, 1951 April 20, 1954 A. J. KASAK 2,675,850

APPARATUS FOR CLAMPING LINING MATERIAL TO BRAKE SHOES 14 Sheets-Sheet 7 INVENTOR AWTm/I/v J. man/r BY AMM ATTORNEY April 20, 1954 A. J. KAsAK 2,675,850

' APPARATUS FOR CLAMPING LINING MATERIAL TO BRAKE SHOES l4 Sheets-Sheet 8 Filed Jan. 25. 1951 INVENTOR AN mw/v J. KAfi/IK ATTORNEY April 20, 1954 A, J, KASAK 2,675, 8 .50

APPARATUS FOR CLAMPING\BINING MATERIAL TO BRAKE SHOES Filed Jan. 25. 1951 14 Sheets-Sheet 10 IN VEN TOR IZA/TON/N J. KLS/IK Maw ATTORNEY April 20, 1954 A. J. KASAK 2,675,350

I APPARATUS FOR CLAMPING LINING MATERIAL T0 BRAKE SHOES Filed Jan. 23, 1951 14 Sheets-Sheet 11 O O 2 Z d 2/2 INVENTOR AW ra/v/ v KAJAK Z .15' 8r [MM ATTORNEY April 20, 1954 'S K 2,675,850

APPARATUS FOR CLAMPING LINING MATERIAL TO BRAKE SHOES Filed Jan. 23, 1951 14 Sheets-Sheet 12 INVENTOR 1.29115 i/ vm/w/v J. A AJAK fiflM AT TORNEIY April 20, 1954 2,675,850

' APPARATUS FOR CLAMPING LINING MATERIAL TO BRAKE SHOES Filed Jan. 23, 1951 A. J. KASAK l4 Sheets-Sheet 13 jflw ATTORNEY April 20, 1954 A. J. KASAK 2,675,850

APPARATUS FOR CLAMPING LINING MATERIAL TO BRAKE SHOES 14 sheets-sheet 14 Filed Jan. 23. l951 IN VEN TOR 14/VT0N/NJ MSHK wmay Patented Apr. 20, 1954 APPARATUS FOR CLAMPING LINING MATERIAL TO BRAKE SHOES Antonin John Kasak; South Bend, Ind., assignor to Bendix Aviation Corporation, South Bend, Ind., a corporation of Delaware Application January 23, 1951, Serial No. 207,374

18 Claims. 1

The present invention relates to apparatus useful in bonding brake lining to a brake shoe, and particularly to an apparatus adapted to clamp a brake shoe and lining assembly together under a predetermined pressure during the period of a bonding cycle.

The process generally followed in bonding a brake shoe and lining assembly together includes the steps of coating the faying surface of the lining or shoe with a thermosetting adhesive, clamping the lining and shoe together under a predetermined pressure, and heating the assembly until the adhesive has cured and produced a secure bond. Various devices have been suggested for carrying out these steps, and some have been adopted by industry for mass producing bonded brake shoes. The present invention is directed to providing useful improvements in the mass production of bonded brake shoes and has for its primary object the provision of an apparatus or mechanism which appreciably increases the rate at which such bonded shoes maybe produced.

It is another object to provide a combination of mechanism which in one form is capable of clamping a brake shoe and lining assembly together and which in another form is capable of unclamping such an assembly while it is being transported along.

It is another object to provide a power clamp mechanism for latching or unlatching a brake bonding fixture adapted to securely position a brake shoe and lining together.

The bonding fixture per se and in combination with actuating mechanism, as herein disclosed, are claimed in Wesstrom et al. application Serial No. 195,832 filed November 15, 1950.

Still further objects will become apparent as the description proceeds.

In the drawings:

Figure 1 is a diagrammatic illustration of an embodiment of the present invention;

Figure 2 is a partial perspective illustrating the lower front and side portions of the mechanism of this invention, with the bonding fixtures and part of the cam rail construction removed therefrom;

Figure 3 is an illustration similar to Figure 2 but showing the rear and side portions of the mechanism and a few bonding fixtures secured to the mechanism conveyor chain;

Figure 4 is an elevation of the lower front side of Figure 2 illustrating the action of the successive bonding fixtures as they open to dump the shoe and lining assemblies, certain of the fixtures 2 having parts removed therefrom for purposes of clarity;

Figure 5 is a fragmental front elevation of Figure 2 showing the succession of bonding fixtures and two clamping devices for the bonding fixtures;

Figure 6 is an elevation of one set. of bonding fixtures having shoe and lining assemblies clamped therein;

Figure 7 is a top view of two sets of bonding fixtures with certain parts being broken away and certain parts sectioned;

Figure '8 is a fragment of Figure 2 showing the configuration of the cam rail which controls the closing and opening action of the bonding fixtures;

Figure 9 is a side elevation similar to Figure 8 showing certain parts of the complete mechanism in diagram;

Figure 10 is a side elevation of one power unclamping device as it acts on a bonding fixture;

Figure 11 is a bottom view of the device of Figure 10;

Figure 12 is a top view of the device of Figure 10 with various parts being broken away for clarity;

Figure 13 is a partial longitudinal section of the reaction or lower jaw assembly of the device of Figure 10; 1

Figure 14 is a section of the lower jaw assembly taken substantially on section line I l-44 of Figure 13;

Figure 15 is a longitudinal section of the pressure or upper jaw assembly of the device of Figure 10;

Figure 16 is a sectional view of the upper jaw assembly taken substantially on section line l6|5 of Figure 10;

Figure 17 is a fragmental view of one power clamping device as it acts on a bonding fixture;

Figure 18 is an end view of two bonding fixtures as they are unclamped by a device of Figure 10; s Figure 19 is a side elevation of the flexible band assembly of a bonding fixture of Figure 6;

Figure 20 is a top view of Figure 19;

Figure 21 is a diagrammatic illustration of the bonding apparatus control system; and

Figure 22 is a section taken on section line 22-22 of Figure 20.

General description Referring now to the drawings and more particularly to Figures 1 to 3, it is seen that the apparatus of the present invention is vertically disposed. Similar prior art devices have been horizontally disposed with the consequence that considerable floor area was needed to accommodate all of the necessary structure. It is obvious that with this invention, a minimum of floor area is needed thereby reserving the use of valuable floor space, ordinarily occupied by prior art devices, for other machinery.

The apparatus generally comprises a heating oven which may project some twenty or thirty feet above the roof of a two story building in which the apparatus may be housed, and a conveyor 32 preferably of the chain and sprocket type which includes a sprocket assembly 34 j ournaled in the top portion of oven 3Uand two lower sprocket assemblies 36 andtB whichare disposed equidistant from and adjacent to the building floor. The operator of the apparatusstands .facing the front sprocket assembly 38 (see Figure 1) and performs his duties as hereafter will become apparent.

As previously explained, in bonding lining to a brake shoe, it advisable to clamp the shoes and linings together with a predetermined pressure before heating. A bonding fixture 4!] (see Figure 6) is used for this purpose, and. as viewed in Figures 1 to 3 and 5, a succession of these fixtures are secured to conveyor 32 so as to provide an endless chain of fixtures. These fixtures 40 are so arranged that as they are transported along, they will automatically open and close at I predetermined locations; e. g. the fixtures will be open when they are directly in front-of the operator who merely leads them with shoe and lining assemblies, will close thereafter and remain closed until having passed completely through the oven 3% and have reached the horizontal portion of conveyor 32 between sprockets 36 and 38 where they will open to discharge the bonded shoe and lining assemblies.

The complete apparatus is suitably supported by a vertical frame structure 42, comprised of four upright corner posts, which carries the various sprocket assemblies 34, 36, and 38 and other parts and devices to be hereafter described. As will be seen more clearly in Figures 2, 3, and 8, an auxiliary frame is supported by frame 42 and comprises a front section 4% inclined at approximately 60 degrees with the horizontal, a vertical rear section 66, and a horizontal bottom section 48. Actually, this auxiliary frame determines the path of the conveyor 32 and is provided with conveyor tracks 50 (Figure 8) which receive and guide the chains of conveyor 32.

In order to simplify the description, the mechanism parts or assemblies will now be individually described in detail with an explanation following of the manner of their association with the other mechanism parts.

Portable brake shoe assembly holding device.-

Bonding fixture Reference is now mad to the bonding fixtures 40 of Figures 4, 6, and '7, Figure 6 illustrating the manner of securing two-fixtures in end-to-end relation to obtain a single fixture set or assembly 52 which is adapted to handle two separate brake shoe and lining assemblies simultaneously. Each fixture 40 comprises a support or C-shaped frame 54 having a bar member or beam 56 pivoted on the outer end 58 thereof. This beam 56 may be pivoted to open as illustrated in Figure 4 and is provided on its pivoted end with a cam follower arm and roller combination 6B which is engaged by a cam rail to be more fully described hereinafter. The innerendof the beam 56 is formed with a tooth 62 which is engaged by a pivoted latch M to lock the beam 56 in its illustrated position. To unlock beam 56, the latch 54 is merely pivoted out of engagement with tooth 62. The adjacent ends of two frames 58 are bolted together as at St and have their outer ends suitably secured to the chains 68 and 70 of conveyor 32. To obtain structural rigidity, it has been deemed preferable to combine in side-by-side relation two fixture assemblies 52, as viewed in Figure 7, in assembling the fixtures to the conveyor 32, making the endless chain of fixtures 40' consist of successive pairs of fixture assemblies 52. The purpose of this manner of combining fixture assemblies 52 will become apparent hereafter.

Each fixture 40 is provided with a clamping band or backing 12 which is preferably constructed of a strip of flexible spring steel having a width slightly larger than that of a brake lining to be bonded. Apertured fittings or hinge links 14, securedto the ends of this band '12, ar received 0n respective pinslt supported in parallel spaced relation with the inner surface of the frame 54 by means of pairs of spaced linkage plates 78. These plates 78 are removably secured to the end portions of frame 54 by means of bolts 86. Thus it is observed that each band 12 is cradled in theconcave portion of its frame 54 in spaced relation therewith, the amount of spacing being determined by the size of the plates 18 and the spacing of pins 16 from the concave surface of frame 54. It should be understood that this band '52 serves as a backing or reaction member against which a brake shoe and lining assembly may be clamped. Since the band 12 is flexible, it will readily conform to the convex curvature of the brake shoe assembly and serve to equalize the clamping pressure along its entire length; hence, this band 12 may be characterized as an equalizer.

The clamping mechanism of each fixture 40 comprises a pressure member or clamp 82 which consists of a pair of convexly shaped plates spaced apart to straddlea brake shoe Web and rigidly fastened together in any suitable manner. The clamp 82 is universally swivelled at 8G to one end of a pin 83 which is reciprocably received in a transverse opening 88 in the central portion of clamping lever or beam 56. The pin 86 and opening 83 are preferably splined to prevent relative rotation, and the end at of pin 86 is provided with nuts 92to retain the pin 36 in assembled position.

The clamp 82 and beam 56 are normally forced apart by a pair of relatively strong springs 94 fitted into sockets 95 in beam 56 on opposite sides of opening 88 to bear against opposite ends of a yoke 96 which is centrally apertured to receive pin '86. An abutment nut 98 is received on the lower end of pin 86 to be engaged by the yoke 96. As viewed in Figur 6, the brake shoe assemblies are compressed against their respective backings 72 by means of the clamps 82 under the compressive force of the springs 9 It will be obvious that these springs 94 also cooperate with the respective latches 64 to retain beams 56 in their illustrated locked positions. For purposes of convenience in claiming this invention, the combination of beam 56, pin 86, and springs 234 may be characterized as a pressure developing mechanism which carries pressur member 82.

The clamping pressure on the shoe assemblies, as derived from springs 94, found to be satisfactory, is approximately one hundred sixty pounds per square inch of lining area. Other pressures of course may be had by adjustment; how= ever, this pressure has produced more nearly the desired bonding result. Inasmuch as thisrelatively high spring pressur is acting on the engaged latch 64 and tooth 62, a correspondingly high pressure, acting in an opposite direction, is necessary to break the engagement. Therefore, in order to facilitate latching and unlatching tooth 62 and beam 55, the beam 56 and frame 54 are compressed together sufiiciently to spread apart the engaging surfaces of the latch and tooth 64, 62. When this break occurs, the latch 64 may be freely rocked out of latching position, and thereafter the beam 56 may be pivoted out of operative engagement with the brake shoe assembly to accommodate the latters removal.

' It should be mentioned here that the universal swivel connection 84 between the clamp 82 and the pin 66 allows the clamp 62 to rock to solidly engage the concave surface of the brake shoe rim. The combination of the band I2 and the rookable clamp 82 provides a reliable, uniform pressure clamping device which will tend not to distort the shape of the brake shoe. Further, the shoe-engaging edge of clamp 02 may be notched or undulated to permit the fiow of hot air current therethrough for uniformly heating the brake shoe assembly.

A tension spring I00 is preferably connected between adjacent latches 64 to urge them out of engagement with the respective teeth 62 when the beams 56 are sufiiciently depressed.

' To facilitate the latching and unlatching action of each fixture 40, a pair of parallel, oppositely disposed compression surfaces are provided, one surface being formed on beam 56 near tooth 62 and indicated by reference numeral I02 and the other surface being similarly formed on the opposite side of frame 54 and being indicated by reference numeral I04. By bringing the jaws of a compressing clamp or vice against these surfaces I02 and i 04, the beam 56 may be pivoted inwardly against the forces of the springs 94 to break the engagement of latch 64.

A pair of spaced guide bars I06 are formed on the inner end of each frame 54 and serves to guide tooth 62 and latch 64 into engagement.

Operating cam for bonding fixture The only manual operation required of an operator of the apparatus of the present invention is the loading of the bonding fixtures 40 with brake shoe and lining assemblies. The clamping of these assemblies and their discharge after bonding are automatic. In order for the fixtures 40 to be loaded, they must be open as they round the sprocket assembly 38 (see Figure 8) inthe direction of arrow F and remain open for a certain length of their travel as indicated by the letter A.

Upon leaving the loading station A, the fixtures 40 are successively gradually closed by swinging the beams 56 slowly inwardly to clamping position, this gradual swinging action occurring during the travel of the fixtures 40 on conveyor 32. Once closed and latched, the fixtures 40 continue their travels upwardly through the oven 30, around sprocket assembly 34, and downwardly through oven 30. Upon leaving oven 30, the fixtures are unlatched, and immediately following this unlatching, the fixtures are again successively, gradually acted upon to open them, this opening action beginning just prior to their rounding rear sprocket assembly 36 (see Figure 9). Then, in traversing the distance between sprocket assemblies 36 and 36, the fixtures are inverted and are completely opened (see Figure 4), the brake shoe assemblies either falling under the force of gravity, or being knocked from the fixtures. The fixtures now being open, are ready for reloading. Thus it becomes apparent that the above-described function is continuous with the operator performing only the single operation of loading the fixtures.

The mechanism for operating the beams 56 of fixtures 40 consists of a length of snakelike cam rail, generally indicated by reference numeral I08 in Figures 8 and 9, which begins just above sprocket assembly 36, passes around sprocket assemblies 36 and 38, and ends a short distance above sprocket assembly 38. Two cam rails I08 are used with one being suitably secured to the inner side of one auxiliary frame section 44, 46, 48 and the other being similarly secured to the other auxiliary frame section. These rails I08 run generally parallel to adjacent, respective conveyor chains 68 and I0 and conveyor chain tracks 50, but are peculiarly shaped at certain locations as will be described later.

' With the fixture assemblies 52 suitably secured to chain 68 and I0, the cam followers 60 thereof are arranged to engage the respective rails I08. Hereafter, since the two rails I06 are formed to substantially the same shape, a description of one will suffice for both. That portion of the rail I08 which passes around sprocket 36, generally indicated by the letter B in Figures 8 and 9, runs substantially parallel to a respective one of the conveyor cains 68 or I0, and is so formed as to be engaged by the roller IIO of fixture follower arm 60. The fixture 40 is in closed but unlatched position as it traverses this portion B and the sole purpose of this portion B is to engage the top side of roller I I0 (as viewed in Figure 6) to hold beam 56 in such closed position.

Next, the roller IIO rides in portion C of rail I06 which is preferably channel-shaped; however, the roller I I0 engages only the side I I2 as viewed more clearly in Figure 4. This portion C is shaped with a degree longitudinal twist to allow the beam 56 to gradually drop open, or fall about its pivot 58, so that by the time the fixture 40 reaches the sprocket assembly 38, it will be completely open and have discharged the brake shoe assembly.

The portion of rail I08 from the end of portion C, around sprocket assembly 36, and through distance A is substantially parallel to the conveyor 32 path and is suitably formed to retain roller I I0 in such a position as will hold beam 56 completely open.

The portion D of rail I06 is provided with a 180 or more degree longitudinal twist and is inclined out of parallel relation with conveyor 32. This portion D is preferably formed of a single fiat section of steel with the surface H4 being engaged by the fixture roller H0. The purpose of this twist is to pivot the follower arm 60 and the beam 56 about the axis 58 to closed position and prepare the fixture 40 for an immediately subsequent clamping and latching operation.

In order to ease the beams 56 downwardly against the force of gravity as they operatively engage portions D, a pair of let-down cam rails H6 (see Figure 5) are mounted on a frame support H8 (see Figure 2) and are arranged to be slidably engaged by the teeth 62 of beams 56 during the latters closing. These rails H6 begin adjacent the locations where the teeth 62 reach the upper crest of their swinging movement and terminate, adjacent the path of the fixture acre-s50 latches 64. The sole purpose of these cam rails' II6 is to provide gradual closure-of beams 56, thereby preventing the mislocation of shoe and lining or damage to the fixturesshould they be freely allowed to fall into closed position under the force of gravity.

Bonding fixture latching and wilt/Itching mechanism.Power clamp In Figure 10 is illustrated a fixture-clamping device generally indicated by reference numeral I28, of which there are four, used to eifect latch.- ing and unlatching of the variousbonding fixtures All as they pass predetermined locations. The two front clamping devices I22 (see Figures 2 and are supported opposite each other on the inclined portions 44 of the auxiliary frame, each device I22 straddling one row of fixtures III, as

illustrated in Figures 5 and 17, to automatically latch them.

The two rear clamps I24 are also supported opposite each other on the vertical, auxiliary frame portions 45, each of these devices I24 likewise straddling a row of fixtures di l, as illustrated in Figure 10, to automatically unclamp and unlatch them. The front power clamps I22 are supported adjacent the trail end its of cam rail I08, while the clamps I24 are supportedadjacent the head or entry end I28 of cam rail Hi3. Hence, the arrangement operates to clamp and latch the fixtures 40 immediately after they leave cam rail end I26 and to unclamp and unlatch them just following their engagement with cam rail end Aside from the latching and unlatching mechanism, the four clamping devices I22 and I24 are identical, so a description ofone will suilice for all.

Referring now to Figure which illustrates the power clamp I24 used on the rear of the present invention as shown in Figure 3, the C-shaped clamp frame I 30 is carried by an auxiliary frame member 46. The shape of this frame IBiI is formed.

by two horizontally extending spaced sides I32 and I34 interconnected by means of a rigid, preferably integral, side I36. As illustrated more clearly in Figure 11, frame I3t is made of two C-shaped side sections I38 and M3 which are rigidly secured together by means of spaced, welded supporting plates I42 and its (shown in dotted lines in Figure 10) and a plurality of bolts I45 and MB. A plate its is hinged to frame mem' ber about a pivot I52, and extends between the two sections wt and I i-ll. This plate I59 is pivotally connected to plate I42 by means of a pin I54 (shown in dotted lines), the axis of which lies in a plane normal to the axis of hinge pivot I52. Thus it is seen that the clamp frame I30 may be tilted or rocked about pivot I52 in the general plane of the frame I353 or may be laterally swung about the pin ltd.

A plate-like extension or supporting-memberportion I56 is suitably rigidly secured to the bottom portion of frame or rigid-supporting mem oer 46, as viewed in Figure 10, to project between the C-shaped side sections I38 and I48. Another pivot pin Iilt having an axis collinear with the axis of pin IE6 is suitably secured to this extension I56 to depend therefrom through an elongated opening its in the lower connecting plate I44. The width of this opening IE5 is coextensive with the diameter of pin I58 while the length is in a direction to permit a limited tilt of frame I39 about hinge pivot I52. Journaled on pin I58 immediately below plate I44 is a grooved roller I62 which is engaged on one pcripheral side by a-tension spring I64 (see Figure 11) connected at one end I66 to frame section I38 and at the other end I58 to an anchoring block I Ill suitably secured to depend from extension I56. This spring Its functions to swivel frame I38 to released position against a, stop I72 (see Figure 11) secured to the edge of extension !56 and serves to yieldably retain the clamping device I20 in released position.

The lower side I35 of frame It!) carries a reaction or lower jaw assembly I14 which is illustrated in detail in Figures 13 and 14. This assembly I'III comprises essentiall two parts; a retainer block I'IS provided with a socket I82, and a T-shaped support block or lower jaw I18 (see Figure 13) the stem I859 of which is rotatably received in socket I82. A thrust bearing ISA is preferably interposed between adjusting screw I in the bottom of socket I32 and the end of stem I80, and needle bearings I36 between the sides of socket I82 and the stem I853. The jaw block I78 is retained on block lit by means of a pair of arcuate plates I88 partially surrounding stem Its to provide diametrically opposite spaces I98 which receive the opposite ends of a pin I92 transversely secured through the center of stem Ital. Thus the swivelling movement of support block I78 is limited by the engagement of pin I92 with the ends of the plates I38. As viewed in Figure 10, a tension spring Its is connected between one end of pin I92 and side I34 of frame I3t thereby yieldabiy rotating lower jaw Ilt to its stopped position as illustrated in Figure 14.

Referring now more particularly to Figures 10, 15, 16, and 18, the pressure or upper jaw assembly IE6 is constructed quite similarly to lower assembly Hi. It comprises a pressure-transmitting-member or bar W8 provided on one end with a clevis 29s and in its other end with a longitudinal socket EiIZ which pivotally receives a stem 2% of T-shaped clamp member or jaw Zilii. Thrust bearings 2G8 and needle bearings are are used to rotatably support stem 29:; in the socket 202. A pair of locking members 2I2, similar to the plates I 88 of Figure 14, are secured to the socket end of bar I93 and are formed with arcuate cutout portions 2M which engage the annular shoulder 2I6 on stem 2% to retain the latter in place. Similarly to the lower jaw assembly I34, a pin 2I8 is secured to stem 2% to lie in the spaces 22% formed between the stop members 2I2. The cooperative function of these stop members 2I2 and the pin ZIE is the same as the similar parts of the lower jaw assembly II I. In order to yieldably retain jaw 2% in the pivoted position illustrated in Figure 16, a spring 222 is compressed between one end of pin H8 and an extension 223 formed on one of the two stop members 2 I2.

Referring to Figures 10 and 18, it is seen that the jaw 2% of the upper jaw assembly I96 and the jaw I'IB of the lower jaw assembly I'III are juxtaposed in cooperative relation to engage the surfaces I62 and its, respectively, of fixtures II This upper jaw assembly I96 is supported by means of a lever 225 which is connected at one end to the clevis 2&9 of bar I98 and at the other end to a pneumatic power cylinder 228. This lever 226 is pivoted intermediate its ends to the end of side I32 at 23 whereby reciprocatory movement of the piston of power cylinder 228 will cause lever 22% to rock about pivot 230, and to raise and lower jaw assembly IQB accordingly.

In order to limit the motion of upper jaw assembly I9I5 substantially in line withthe longitudinal dimension of the bar I 38, a linkage 232 is acmsso may be clamped between jaws I18 and 206 to depress the beam 56 to latch or unlatch it as previously explained.

The power clamp I24, as shown in Figures and 18, is used to unlatch the fixtures 40. This unlatching action is facilitated by use of the fingers 234 pivoted intermediate their ends to extensions on linkages 232. The upper ends of fingers 234 are connected to bar I98 by means of tension springs 236 which tend to rotate these fingers 234 in a counterclockwise direction.

A pair of latched fixtures 40, as illustrated in Figure 10, are acted upon by this powerclamp I24 in the following manner. As the fixtures 40 pass between the spread jaws I'I8and 206, the power cylinder 228 is energized to rock lever 225 in a clockwise direction. The jaws I18 and 206 are brought into engagement with the fixture surfaces I 04 and I02, respectively, and simultaneously, the lower-tapered end of each finger 234 engages the inner inclined side of the respective fixture latch 64. t The combination of the power cylinder 228 and lever 226 is sufilciently powerful to compress the surfaces I02 and I04 toward one another against the action of springs 94 whereupon'the engagement between the teeth 62 on beams 56- and the latches 64 are broken allowing the springs 236 and fingers 234 to pivot the latches 64 clockwise out of engagement with the teeth 62. Power cylinder 228 is now oppositely energized, and the jaws I18 and 206 thereby separated tov allow the fixtures 40 to continue on their course. The actuation of the power cylinder 228 is automatic and a system for controlling its actuation will be described hereinafter.

Referring now to Figures 2, 5, and 1'7, the power or latching clamp I22 is illustrated as being provided with a latching mechanism generally indicated by the reference numeral 238. This mechanism 238 is comprised of'an elongated cam 246 which is pivotally connected to the upper jaw assembly bar I98 by means of a linkage 242. This cam 240 is provided at its lower end with alongitudinal slot 244 arranged to receive a pin 246 extending laterally from the end of motion-stabilizing linkage 232. A tension spring 24'! is connect-:1

ed between the upper end of bar 246 and the pin 246 whereby the cam 240 is yieldably urged downwardly.

Assuming that the latch 54 is disengaged from tooth 62, as illustrated by the dotted lines of latch 64, power cylinder 228 is actuated to compress the fixture surfaces I02 and I04 together. With a downward'movement of theupper jaw assembly I96, spring 241, in the latching mechanism 236, draws the cam 240 downwardly until cam surface 248 engages the outer sideof latch 64. Once the fixture surfaces I02 and I04. have been pressed sufiiciently close together, latch 64 will be rotated counterclockwise by the action of spring 241 and cam surface 248 until the latch overlies the upper surface of tooth 62. The jaws of the power clamp I22-are now released allowing thebeam 56 to pivot outwardly underthe-pressure of springs 94 until thetooth 62 engages and frictionally locks with latch 64.

.Figure 18 is a front I24 as it engagestwo successive bonding fixtures 40. Inasmuch as, two fixtures" may be acted elevation of thepowerclamn upon simultaneously, it is desirable to secure two bonding fixture assemblies 52 together as shown in Figure 7 to obtain the required rigidity for the clamping or compressing action.

Control mechanism now be described. Air valve actuating mechanisms are indicated generally by reference numerals 256 and are carried between the sprocketassemblies 36 and 36 by the horizontal frame section 48 of the auxiliary frame. There are two mechanisms 256 carried by each of the two frame sections 48, one mechanism controlling the operation of one power clamp, such as I22, and the other controlling a power clamp E24. Inasmuch as the mechanisms 250 are identical, a description of one will sufiice for all.

A pivot shaft 252 is journaled in frame section 48 and is secured on one end to a trip arm 254 which lies parallel and adjacent to the conveyor rail 50. A cam plate 256 is secured on the end of arm 254 and is positioned to be engaged by the cam studs 258 (Figure 6) on bonding fixture assemblies 52. It should be noted that these cam studs 258 are secured on the fixture frames 54 immediately adjacent the conveyor chains 58 and I0, and thereby travel along a predetermined path parallel to the conveyor chain guides 50 (Figure 8). The trip arm 254 positions cam plate 256 in the path of studs 258 whereby the shaft 252 will be rocked each time a stud rides against plate 256. On the other end of shaft 252 is secured a valve-actuating arm 260 which momentarily. opens normally closed air valve 262.

Referring now more particularly to Figures 11 and 21, the power clamp I24 is operated in the following manner. The studs 258 are spaced along the conveyor chains 68 and I0 a predetermined distanceapartso that as one stud 258 engages a valve actuating mechanism 250, the correspond- 206. The power clamp I24 is normally pivoted against its stop I12 (see Figure 11) by spring I64, and the moment this clamp I24 grasps a pair of fixtures 46, the jaws I18 and 266 are necessarily carried along with the fixtures. This pivots clamp I24about pins I54 and I58 andjaws H8 and 2.06 pivot in their respective sockets I82 and 262 (see; Figures 13 and 15).

, Inasmuch as it is necessary for clamp I24 to remain engaged withlthe fixture 42. only long enough for them to be unlatched, a valve is arranged to be actuated after a certain pivotal movement of the clamp I24 to release the fixtures 46 and allow the pivotal return of clamp I24 against its stop H2 by springl64. Thus, the clamp I24 is readied for another fixtureeengaging action. This releasing valve is indicated by-reference numeral 210 and is preferably secured to extensionl56 of vertical frame section 46. clamp I24 rotates in a-clockwise' direction, as viewed in Figure 11, concomitant with thetravel of the clamped fixtures 46,'it eventually engages and operates valve-2113 which is opened (see Figure 21) to send air pressure to master control valve 2&5 which operates to exhaust the pressure in power cylinder 228 and to connect tube 212 with the other end of power cylinder 228 to force the piston inwardly and open the clamp jaws I18 and 206. Thus when these jaws I18 and 206 are disengaged from the fixtures 4|], the return spring I64 pivots the power clamp I24 to released position against stop I12.

This clamping and unclarnping cycle repeats itself for each pair of fixtures 4!] which passes between the power clamp jaws, and the four power clamps I22 and I24 are individually operated as predetermined by the spacing of cam studs 258 and the locations of the four valve actuating mechanisms 25!). With this particular control system, it is obvious that a single mechanism 252 in combination with one master air valve 266 serves only one power clamp I22 o-r I24.

The bonding fixture clamping band The clamping band 12 in Figure 6 is more clearly illustrated in Figures 19 and 20. This band 12 consists of two parts, the first being a master band 214 and the second a locator band 216 which is removably secured to one surface of master band 214. Master band 214 is preferably formed of a strip of flexible spring steel having relatively high tensile strength and is provided on its ends with hinge plates 14 adapted to receive through the openings 218 thereof the respective pins 16.

The locator band 216 is preferably a stamping formed to an arcuate shape and with a plurality of longitudinally spaced ears 28!] on the longitudinal edges thereof. As viewed in Figure 22, each ear 280 is bent to provide stepped portions 282 and 284, portion 282 being offset outwardly from portion 234. The length of portion 254 is formed coextensive with the normal thickness of a brake lining segment 28 6 and the distance across the band between these portions 284 of opposite ears 280 is made equal to the normal width of the lining segment 286. Thus the lining segment may be laterally positioned with respect to band 216. The rim 288 of a T-section brake shoe is similarly laterally positioned by the ear portions 282. The lining 28B is longitudinally positioned by means of an abutment 292 on one end of band 215 while the corresponding end of the brake shoe rim 288 is likewise placed against a similar abutment 292 thus completing the operation of locating the lining segment 226 with respect to shoe rim 288.

The locator band 216 ha one end formed to fit in a transverse slot 294 in one hinge plate 14, and its other end engaged by the head of a cam screw 296 fitted to the other hinge plate 14. The head of screw 296 is formed with one flat side so that by rotating this screw 180 degrees from its illustrated position, the engagement with the end of band 216 will be freed thereby allowing the latter bands ready removal.

Operation The foregoing description of the embodiment of the present invention has included the operation thereof; however, a brief review of this operation will now be given.

The arrow F in the various figure (see Figure 2) indicates the direction of travel of conveyor 32. As the fixture assemblies 52 round sprocket assembly 38 and pass in front of the operator (see Figure 1) the fixtures are open and ready for loading. The operator first positions a lining segment, such as the one 286 of Figure 22, on the clamping band 12 and then a brake shoe on top of the segment. Thereafter the operations of this invention are automatic with the loaded fixtures being first closed by the surface [It of cam rail I98 (see Figure 8) and then clamped and latched by power clamp I22. The brake shoe and lining assemblies in the latched fixtures 40 are now pressed together under sustained pressure and are transported upwardly and then downwardly through oven 30. I Immediately upon leaving the oven, the fixtures are unclamped and unlatched by power clamp I24 (an unlatching power clamp is illustrated in Figure 10). and thereafter operatively engage the cam rails I08 which cause the fixtures to swing open as they pass inverted between lower sprocket assemblies 36 and 38 to dump the brake shoe assemblies. The fixtures, now being open, are ready to accept other brake shoe assemblies.

Although only one embodiment of the invention has been illustrated and described, various changes in the form and relative arrangements of the parts may be made to suit requirements.

I claim:

1. An apparatus for developing pressure comprising a rigid support having two spaced sides providing end connecting portions, a supporting section provided on one of said connecting portions and having a socket, a first jaw member consisting of a support block and a stem which projects into said socket, a first pivot limiting means secured to said supporting section and partially surrounding said stem, a pin transversely projecting through said stem, said pivot limiting means being provided with diametrically opposite cutaway portions which loosely receive the ends of said pin to allow said stem only limited pivotal movement in its socket, a lever fulcrumed on the other of said connecting portions, a pressure-transmitting member having a socket and being pivotally connected to one end of said lever, a second jaw member consisting of a pressure block and a stem, said latter stem having a shoulder portion adjacent said pressure block and being pivotally received in said pressure-tr-ansmitting-member socket, a locking means secured to said pressure-transmitting member and engaging said shoulder to hold said latter stem in its socket, a second pin transversely projecting through said latter stem, said locking means being provided with diametrically opposite cutaway portions which loosely receive the ends of said second pin to allow said second stem only limited pivotal movement in its socket, said jaw members being positioned with respect to each other to clamp an object therebetween, and a link pivotally connected between said pressuretransmitting member and said other connecting portion acting in conjunction with said lever to permit only substantially translatory'motion of said pressure-transmitting member.

2. An apparatusfor developing pressure comprising a rigid support having two spaced sides providing end connecting portions, a, supporting section formed on one of said connectingportions and having a socket, a first jaw member consisting of a support block and a stem, said stem being pivotally received by said socket, a pivot limiting means secured to said section and partially surrounding said stem, a pin transversely projecting through said stem, said pivot limiting'means being provided with diametrically opposite cutaway portions which loosely receive the ends of said pin whereby said stem is capable of only 

